Aliens in the U.S - What, according to you, are illegal alien networks

Aliens in the U.S.

What, according to you, are illegal alien networks? Explain how and what they do to facilitate illegal alien entry and the acquisition of documents, and to assist in reaching a final destination.
Alien networks are loosely related but are distinct to their function and geographic area. Explain these distinctions with the help of appropriate examples.
In what geographic areas would pro-immigrant groups concentrate their network activities? Why? What two strategies would you employ to break this nexus?